The present invention pertains generally to the printing industry, and more particularly to a method for rapidly raising and lowering the feed and delivery tables of a printing press.
When sheets of paper are run through a printing press, the process is known as feeding. When paper is placed into the press the process is known as loading. When paper is placed into the press the paper is placed onto a platform called a feed table. The exact point at which paper is fed into the press to be printed upon by the machine is approximately 3 feet off of the ground. Before paper can be loaded into the press for printing the feed table must be lowered approximately 2.5 feet via means of a chain system operated by a crank handle. To lower the table 2.5 feet the crank must be turned approximately 55 revolutions as quickly as possible to limit non-production time or down time. After a while this can become quite tiresome and repetitive. The act of raising or lowering the feed and delivery tables also requires the operator to be in a bent over posture causing strain on the printing press operator""s back.
For example assume that an order was received for 50,000 #10 printed envelopes. #10 envelopes can only be printed 500 at a time. To run this order, 500 unprinted envelopes are placed upon the lowered feed table to be printed. The feed table must then be raised by the crank handle until the top of the stack of envelopes reaches the correct point where the printing press is able to draw the top envelope into the press via an air suction system to be printed. As the envelopes are constantly pulled into the press to be printed the stack is depleted. At these times the press has a device known as a bale bar which moves in an up and down motion, the down motion stops when the bale bar comes in contact with the top of the stack of paper which is constantly depleting due to paper or envelopes being pulled into the printing press to be printed. The feed table is then automatically raised by the press in small increments to keep the upper most sheets of the stack of paper, envelopes etc. in the correct position to be fed into the press for printing. To print on 50,000 envelopes 500 at a time (100 boxes of #10 envelopes) the feed table must be lowered by the hand crank a total of 5,500 revolutions. To use the handle it must be pushed in where two squared cutouts on the inside of the handle intersect with two squared outcroppings on the printing press and held in place. The handle is not permanently attached to the printing press, however it is normally left in position to perform the cranking operation.
Also, where the paper comes out of the printing press, it lands on another table known as the delivery table. This table is very similar to the feed table. The delivery table can be set to go down as the amount of printed sheets accumulate. Once the table reaches the bottom, the printed materials are removed and the table must be re-raised by another hand crank.
Devices for assisting in manual cranking or turning operations are well known in other art fields. For example, U.S. Pat. No. 2,465,048 shows a wrench head for tightening wing nuts which is adapted to be driven by a rotating tool such as a torque screwdriver or the like. The invention tightens wing nuts with improved speed and efficiency.
U.S. Pat. No. 3,086,414 is directed to a combination wrench of the socket type having a cylindrical stem, a free end having an axial bore of a diameter sufficient to provide clearance for the screw to which a nut is to be threaded, and plurality of cut away portions.
U.S. Pat. No. 3,868,874 illustrates an insulative torque coupling assembly for electrical device terminals. The device includes a bolt engaging a bolt passing through an aperture in a terminal of an electrical device. U.S. Pat. No. 4,984,489 defines a window handle turning drive-limiting tool for a hand drill which cooperates with the crank handle of the opening mechanism of a casement window. The drive-limiting tool includes a shaft which is intended to be gripped by the chuck or jaws of the hand drill in much the same manner that hand drills grip drill bits. A forwardly projecting crank handle-contacting head is provided which is adapted to slide over the crank handle.
U.S. Pat. No. 4,846,025 pertains to a tool for removing radiator caps. The tool has a hollow handle and a flanged hollow face. The hollow face has a recess with a perimeter. The perimeter has a pair of opposed rectangular indentations, at least one pair of opposed arcuate indentations, and a pair of tapering indentations which interrupt the perimeter to form a pair of opposed openings.
U.S. Pat. No. 5,433,850 discloses an adapter to operate a honey extractor utilizing a power drill. The adapter engages the drive shaft axially of the honey extractor after removal of the handle which is used for manual operation to connect the drive shaft to a power drill. The adapter is conveniently a socket to engage an end of the drive shaft, the socket having a prong for insertion in the chuck of the power drill.
U.S. Pat. No. 5,697,268 portrays a wing nut driver. The device includes a cylindrical housing having a bore at one end for receiving the wing nut therein.
U.S. Pat. No. 5,896,785 comprises an automobile gas cap removal tool, formed of plastic aluminum having a bell shape with channel formed by the wall segments and a pillar or shaft extending from the top of the bell segment to a handle mounted on the opposite end of the pillar extending from the bell segment.
U.S. Pat. No. 5,996,447 consists of a sink wrench for engaging a faucet mounting nut, the wrench including an elongated tubular pipe which has slots at one end.
The present invention is directed to a method for using a drive-limiting tool to raise and lower the feed and delivery tables of a printing press. The tool, in combination with a power drill, replaces the manual hand crank which is classically used to raise and lower the tables. The present invention eliminates operator fatigue, increases production, reduces down time, and increases employee moral which comes with the knowledge of not having to crank the feed or delivery table handles any longer. The drive-limiting tool of the present invention is inserted into a common hand held multi-speed reversible phased power drill and firmly secured with a chuck key. The printing press crank handles are removed and the drive-limiting tool is aligned with the rotatable member on the printing press. The feed and delivery tables can then be raised or lowered using the power drill. The speed of the raising or lowering of the feed and delivery tables is increased by a factor of about four depending on the power of the drill. When the tables reach either the top or the bottom in the printing press they come to a halt. The beveled edges allow the drive-limiting tool to xe2x80x9cpop outxe2x80x9d and not damage the printing press.
Advantages of the Present Invention:
The drive-limiting tool of the present invention replaces the hand cranks on the feed and delivery tables of small offset printing presses.
It can be used alternately on the feed table drive or the delivery table drive on any number of printing presses without installation.
Eliminates operator fatigue, increases production, decreases downtime and increases employee moral which comes with the knowledge of not having to crank the feed or delivery tables any longer.
The drive-limiting tool is constructed of aluminum which is a softer metal than the printing press is constructed of thereby preventing undue wear and tear to valuable printing equipment.
The drive-limiting tool can be used with the feed or delivery drives on numerous types of printing presses without installation and is simple to use. Some types of presses the drive-limiting tool could be used with include the Ryobi 3302M, Ryobi 3200CD, Ryobi 3200NP, Itek 3985, Itek 960, Itek 975 and can be easily redesigned to fit other small printing presses such as Hamada printing presses, Multigraphic printing presses, Heidleberg printing presses and AB Dick printing presses to name a few.
The drive-limiting tool also greatly increases the speed of the raising and lowering of the feed and delivery tables.
In accordance with a preferred embodiment of the invention, a method for raising and lowering a table of a printing press, includes:
(a) providing the printing press having a rotatable member for raising and lowering the feed and delivery tables, the rotatable member having a longitudinal axis, two spaced protuberances having walls disposed substantially parallel to the longitudinal axis of the rotatable member, and a central outwardly projecting shaft, the table having an uppermost position and an opposite lowermost position and a table raising and lowering mechanism, wherein the rotatable member can only raise or lower the table between the uppermost and lowermost positions, and the rotatable member experiencing rotational resistance and ceasing to rotate when the table reaches either of the uppermost or lowermost positions;
(b) providing a drive-limiting tool having:
a front portion;
an opposite rear portion;
a longitudinal axis;
the front portion shaped and dimensioned to engage the rotatable member of the printing press;
the front portion having a slot for receiving the two spaced protuberances;
the front portion having a central hole for receiving the central outwardly projecting shaft;
the slot having two outwardly opening walls which slope outwardly with respect to the longitudinal axis of the drive-limiting tool; and,
the rear portion having an axially projecting drive shaft;
(c) providing a power drill;
(d) installing the drive shaft of the drive-limiting tool in the power drill;
(e) engaging the rotatable member with the front portion of the drive-limiting tool;
(f) activating the power drill so that the drive-limiting tool rotates the rotatable member;
(g) continuing to activate the power drill until the table reaches one of the uppermost position and the lowermost position wherein the rotatable member experiences rotational resistance and ceases to rotate; and,
(h) when the rotational member ceases to rotate, because of the slope of the walls of the slot, the walls are urged away from the protuberances thereby causing the drive-limiting tool to disengage from the rotatable member, thereby preventing the table raising and lowering mechanism from being overdriven. The disengagement also prevents damage to the power drill, and possible injury to the printing press operator.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.